code: def test_to_json_with_get():
      from dask.multiprocessing import get as mp_get
  
      flag = [False]
  
      def my_get(*args, **kwargs):
          flag[0] = True
          return mp_get(*args, **kwargs)
  
      df = pd.DataFrame({"x": ["a", "b", "c", "d"], "y": [1, 2, 3, 4]})
      ddf = dd.from_pandas(df, npartitions=2)
  
      with tmpdir() as dn:
          ddf.to_json(dn, compute_kwargs={"scheduler": my_get})
          assert flag[0]
          result = dd.read_json(os.path.join(dn, "*"))
          assert_eq(result, df, check_index=False)
  
imports: from __future__ import annotations
  import json
  import os
  import fsspec
  import pandas
  import pytest
  from packaging.version import Version
  import dask
  import dask.dataframe
  from dask.dataframe._compat import PANDAS_GE_200
  from dask.dataframe.utils import assert_eq
  from dask.utils import tmpdir, tmpfile
label_desc: Use image node_id 12 for calling a global function with example usage: test_to_json_with_get() and returns: mp_get